Casio developed its first calculator in 1957, but it was not until 1974 with the release of the Casiotron that Casio entered the watch making a market. 

G-Shock is a brand of watches manufactured by Casio, known for its resistance to shocks (e.g. hard knocks and strong vibrations). Its full form

Casio developed its first calculator in 1957, but it was not until 1974 with the release of the Casiotron that Casio entered the watch making a market. 

G-Shock is a brand of watches manufactured by Casio, known for its resistance to shocks (e.g. hard knocks and strong vibrations). Its full form is Gravitational Shock. They are designed primarily for sports, military and outdoor adventure oriented activity; nearly all G-Shocks have some kind of stopwatch feature, countdown timer, light and water resistance.

Product Features:

• Mineral Glass
• Shock Resistant
• 200-meter water resistance
• Case / bezel material: Resin
• Resin Band
• Electro-luminescent backlight
• Auto light switch, afterglow
• Flashes with buzzer that sounds for alarms, hourly time signal, countdown timer progress beeper, and stopwatch auto start
• World time
• 29 time zones (48 cities), city code display, daylight saving on/off
• 1/100-second stopwatch
• Measuring capacity: 23:59'59.99''
• Measuring modes: Elapsed time, split time, 1st-2nd place times
• Other: 5-second countdown auto start
• Countdown timer
• Measuring unit: 1 second
• Countdown range: 24 hours
• Countdown start time setting range: 1 minute to 24 hours (1-minute increments and 1-hour increments)
• Others: Auto-repeat, progress beeper on/off
• 3 multi-function alarms (with 1 snooze alarm)
• Hourly time signal
• Full auto-calendar (to year 2099)
• 12/24-hour format
• Button operation tone on/off
• Regular timekeeping: Hour, minute, second, pm, month, date, day
• Accuracy: 15 seconds per month
• Approx. battery life: 10 years on CR2025
• Size of case:46.843.213.6mm
• Total weight: 52 g